I think you very boring.病句哈?

i think you are very boring.(正确）
这是一个复句，i是主语think是谓语，you是宾语，are very boring是宾补
you are very boring是个完整的句子，所以需要主谓宾都齐全。

I think you are very boring

句子中没有动词，如没有动词不叫句子

把boring改成bored
人+ed 物+ing

是的。正确的是I think you are very boring